Since Mycoplasma bovis was detected on their property in July last year, Kerry and Rosie Dwyer have gone through some "very dark moments''.But there had also been some heartwarming and humbling times for the North Otago farmers who voluntarily sent 400 calves to slaughter and now face an undefined period before they can be rid of the impact of the bacterial cattle disease.

Mr and Mrs Dwyer were grateful to their friends, neighbours and colleagues for their understanding and empathy, and those Ministry for Primary Industries and AsureQuality staff who had been practical and hardworking to help them find solutions to "so many problems''.

The couple also thanked the rural contractors and service providers, the meat company and transport companies willing to work with them and the employers and employees who had stuck with them through the process.

They also were grateful to a neighbour who went "ballistic'' on National Radio one day - concerned about the arrival of the disease in the district - giving them perspective on coping with stress.

The stress Mr and Mrs Dwyer had endured over the past few months had been immense and wide-ranging in its causes.

It started with finding out they had a disease on their farm for six months or more - having purchased calves from Van Leeuwen Dairy Group where the disease was first detected in New Zealand - yet there were no symptoms in their calves and there was no cure.

There was no practical way to save some animals within an infected herd, because the testing regime available was not good enough to make that a feasible way to gain a guaranteed clean herd.

They then had to tell all the people they dealt with through their calf rearing business and explain the possible implications, and then wonder for months whether they had passed it to their many clients via the calves they purchased. Fortunately, the bug stayed within their family.

Defining quarantine conditions and systems, that were also acceptable to MPI, were not simple on a working property.

"Our understanding of agriculture and animal management is not shared by all the people we were dealing with,'' Mr Dwyer said.

They also knew that any breach of MPI restrictions could result in fines at least - and loss of possible compensation at worst.

The couple had to feed and care for calves knowing they would die prematurely. Future stress on those calves would lead to disease symptoms and, therefore, animal welfare issues, which was why they forced the process to have them slaughtered before getting to that position, he said.

He then had the difficult task - both emotionally and physically - of loading all 400 calves on trucks by himself so it kept the truck driver ``clean'' in the quarantine system.

While they had encountered some good staff from MPI, they also had to deal with "lack of policy, indecision, change of policy, belligerence and lack of communication'' from other parts of the organisation.

Before speaking to the Otago Daily Times earlier this month, the Dwyers had not spoken out about their ordeal, and had to ``sit in silence'' while reading and hearing so much publicity around the disease response ``knowing that much was misdirected''.

When asking for assistance from some industry organisations, the response was either hesitant or unwilling, he said.

Sheep breeding was a passion for Mr Dwyer, who has had a Suffolk stud for 41 years. The possibility that his stud sheep might have contracted the disease would have been the "last straw'' but fortunately his flock tested negative.

A national bulk milk survey - as part of a large surveillance and testing operation to build a picture of where the disease is - was on track to be completed by the end of the month, MPI's latest stakeholder update said.

So far, more than 55% of farms have submitted their second test of three and 16% of farms completed all three rounds of testing. There were currently 27 confirmed infected properties and 47 under restricted place notices.

When asked about any breaches of restrictions on affected properties, an MPI spokesman said a ``handful of minor breaches'' relating to cleaning and disinfection had been identified but there had been no major breaches, such as unlawful movement of animals, which was the principal means of disease spread.

None of the breaches were considered to have been high-risk in terms of spread of Mycoplasma bovis. While there have been ``small numbers'' of education and warning letters issued, there have been no breaches leading to MPI taking prosecution action.